A motor vehicle crash involving a Virginia fire engine has brought to the forefront an issue that has been discussed, if not debated, many times privately by fire, police and EMS chiefs.
That issue is whether emergency vehicle drivers have become overly dependent on pre-emptive traffic devices (those designed to automatically change the traffic signals at an intersection to green in the direction of an approaching emergency vehicle).
Before I continue, let me say that in my career, I have had two accidents and several near misses while responding to emergency calls.
The most serious occurred at night, when another vehicle pulled out of a private driveway along a straight stretch of a two-lane highway and crossed directly in front of me. That incident sent four people to the hospital, and I can still remember how everything went in slow motion when I saw the other driver’s eyes growing larger as he realized that his car wasn’t going to clear my path.
In this latest incident, the police have charged the fire apparatus operator with “failure to yield the right of way at a [red] traffic signal.” The crash sent four people, including the apparatus operator, to the hospital.
Initial reports indicated that the engine was traveling with lights and sirens to the report of a structure fire when it approached the intersection.
The report thus far has not said if the apparatus slowed down as it approached the red light at the intersection. In most states, including mine in Ohio, when approaching a red light, due diligence calls for the apparatus to slow and then stop completely if the signal is red.
The report does seem to indicate that a pre-emptive traffic control device was present at the intersection, but that the light was clearly green for the traffic crossing the path of the fire engine.
How pre-emptive traffic devices work
Pre-emptive traffic devices can use different types of technology to assist emergency vehicles with traffic control:
- Siren activated,
- Light activated (usually a light in the infra-red spectrum) and
- GPS activated.
Both the siren- and light-activated systems can have dead areas where curves, hills or buildings can temporarily block or diminish the sound or signal from the emitter on the apparatus.
The GPS, while usually unaffected by terrain, can at times be affected by other conditions. Like any other electronic device, the signal from the GPS in the apparatus can be affected by:
- A voltage drop,
- Dislodged cable or
- An extreme weather condition.
Another issue is when two or more emergency vehicles approach an intersection simultaneously. The pre-emptive system has to decide which direction to switch to green:
- The nearest,
- Strongest or
- First to arrive.
For example, would it favor a 200-watt siren on an engine rather than a closer 100-watt siren on a staff car?
Thus, the operators controlling these vehicles cannot rely solely on their presumption that the traffic signal will be green for them as they approach an intersection.
I’ve found two relatively recent studies on pre-emptive systems:
- The United States Department of Transportation: Traffic Signal Pre-emption for Emergency Vehicles: A Cross-Cutting Study
- Hildebrand A. “Crisis Response Journal”: Getting to Incidents Safely
Both are worth the time to look up and read.
What can we take away from this unfolding investigation as chiefs, officers and fire apparatus operators:
- First, each department should review its training to be assured that its defensive driving and vehicle operators’ class discusses the pros and cons of pre-emptive systems, especially those in their immediate jurisdiction and those in their automatic or mutual districts.
- Second, and probably most important, is to instill in these drivers that a pre-emptive system is not infallible. It doesn’t eliminate the need to approach every intersection with caution and be prepared for the unexpected by slowing down, coming to a complete stop for any red traffic signal and ensuring opposing traffic is stopped before proceeding through the intersection.
Driving emergency apparatus is a serious responsibility. The lives of your fellow firefighters, those driving around you and the citizens we are responding to help all depend on you and your judgement to drive safely.
Stay safe.
